1. Field of Invention
The present invention relates to a signal converting apparatus (SCA) between an analog signal and a digital signal, and particularly to a signal converting apparatus (SCA) for integrating an analog-to-digital converter (ADC) and a digital-to analog converter (DAC) and an integration unit thereof.
2. Description of the Related Art
FIG. 1 is a block diagram showing a conventional processing structure of analog and digital signals. In general, an ADC 110 and a DAC 130 are two independent analog circuits designed separately. For converting an analog signal A1 into a digital signal D1, the analog signal A1 should be converted into a digital signal D1 by the ADC 110 first, then sent to a processor 120 (for example, a digital signal processor DSP) to process the digital signal. If the digital signal D2 output from the processor 120 is to be converted into an analog signal A2, the DAC 130 converts the digital signal D2 from the processor 120 into an analog signal A2 for output.
In real practice, however, there is little chance to conduct signal converting of both ADC and DAC simultaneously. In other words, only one converter, either the ADC 110 or the DAC 130, converts signals, while the other converter is idle. Thus, the circuit utility rate is low.